An interdisciplinary basic research and training program involving toxicologists, geneticists, microbiologists, chemists and engineers at the University of Cincinnati has been underway during the past 2.5 yrs, aimed at reduction of risk to human health through the development of new methods for detection of hazardous substances and the development of advanced microbial systems to biodegrade major categories of hazardous compounds in the environment. The long term research objectives of this application are to extend the discoveries and results we have generated in order to address basic research questions related to the detoxication and biodegradation of complex mixtures of hazardous compounds. The proposal calls for a training and administrative core, and seven projects. Proj. 1 deals with the development of cytochrome P450 detoxication systems in yeasts, and with the examination of gene probes for monitoring the survival and growth of such microorganisms in biofilms and other microbial populations. Proj. 2 examines novel bacterial isolates and microbial consortia for the aerobic detoxication and degradation of azo and chrome dyes and related dye stuffs. Proj. 3 involves the genotoxicity and microbial biodegradation of 4 and 5 membered ring aromatic hydrocarbons and N-heterocyclic compounds that are characteristic of mixtures at coal gasification waste sites. Proj. 6 seeks to understand the mechanisms of chromium mutagenesis, using genetic targets in shuttle vectors in mammalian and yeast cells, and in vitro DNA replication systems. Proj. 5 examines novel approaches in chromatography/plasma mass spectroscopy in ultra-trace analyses of chromium speciation and other species and compounds. Proj. 7 examines the operational properties of biofilms in relation to the biodegradation of azo dyes, including the modeling of substrate transport and of chemical reactions in biofilms, and examining the efficiency of anaerobic/aerobic reactor sequencing. Proj 8 studies biodegradation in the green plant/soil/microflora of the rhizosphere. Interdisciplinary, collaborative effects by the several investigators constitutes a defining characteristic of the overall research program. Research collaborations also are the basis of an interdisciplinary program for recruiting and training of MS and PhD graduate students and postdoctoral fellows. This program provides vigorous training in a research discipline plus broad experience in the problems and approaches to reducing the hazards to human health caused by toxic waste sites.